THE CICADA. 39 



10. What peculiarity has the prothorax? 



11. Study the abdomen. How many segments? 

 Do you find any spiracles? Where? 



12. Cut off the wings and find the nerve cord. 

 How does the nervous system differ from that of the 

 grasshopper? 



13. Look at the larva and say whether the giant 

 water bug has a direct or an indirect metamorphosis. 



Additional Facts About the Giant "Water Buj?. 



The giant water bug lives in ponds, and flies 

 around at night. It is attracted in great numbers to 

 electric lights, and is sometimes called the electric- 

 light bug. There are two kinds, the Belostoma 

 americanum, in which the femur of the fore leg is 

 grooved to receive the tibia, and Benacus griseus, in 

 which the front femur is not grooved. 



The giant water bug is quite destructive to min- 

 nows and young fish, piercing them with its beak. 

 Parasites are frequently found on giant Avater bugs, 

 one of the most common forms being Hydrachna 

 belostomse. 



A smaller insect, Zaitha fluminea, much like the 

 giant water bug, and living in the same situations, 

 may be used for this study. The squash bug is also 

 very good. 



THE CICADA. 



1. Identify the body divisions. 



2. Study the eyes, ocelli, antennae. 



3. Examine the mouth parts. See the punctorial 

 bristle. Of how many parts is it composed? 



4. Notice the wings. How do they differ from the 

 wings of the giant water bug? 



5. Study the legs. How does the first pair differ 

 from the other legs? 



